A tire noise reduction system

Abstract

The present application relates to the field of tire manufacturing technology, and in particular to a tire noise reduction system. The tire noise reduction system comprises a pneumatic tire having a cavity, the pneumatic tire having a tread portion, a bead portion, and a sidewall portion. The inner wall of the tread portion is provided with a strip of sound-absorbing cotton bonded with an adhesive. The strip of sound-absorbing cotton is provided with one or more continuous annular holes along the circumferential direction. The strips of sound-absorbing cotton are connected end to end, and the annular holes are also connected end to end to form a large annular sound-absorbing cavity that is not connected to the inner cavity of the tire. The strip of sound-absorbing cotton is a sponge-like porous material made by foaming a polymer material, with an apparent density of 5 kg / m 3 ‑50kg / m 3 The sidewalls of the annular hole connect to the porous strips of sound-absorbing cotton, connecting the large annular silencing cavity with a large number of porous silencing cavities. Through implementation of the present invention, it was found that this large main silencing cavity combined with numerous small silencing cavities can suppress cavity noise over a wide frequency range.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of tire manufacturing technology, in particular to a tire noise reduction system. BACKGROUND

[0002] The noise of the tire when driving, generally has external noise, such as pattern noise, road noise, and internal cavity noise. Among them, the tire cavity noise is caused by the resonance of the ultralow pressure sound system composed of the tire and the disc wheel, which is usually called tire resonance sound.

[0003] The cavity noise frequency is between 200-300Hz, which is determined by the tire cavity structure.

[0004] In the cavity inside the tire, the sound absorber made of sponge-like material is a known method to reduce cavity noise. The mechanism of sponge-like sound-absorbing cotton as a sound absorber is that there are countless air micro-pores inside the sound-absorbing cotton, which can buffer and absorb sound waves, making it difficult for sound waves to be reflected again at the plane of the sound-absorbing cotton. Therefore, in the past patents, the density of the sound-absorbing cotton is strictly regulated, such as patent CN110395976A which specifies that the density of the sound-absorbing cotton needs to be between 40g / m3-50kg / m3, otherwise it cannot achieve effective results. However, this method still has a large space for improvement in reducing the degree of cavity noise. Because the frequency of cavity noise is between 200-300Hz, and the pore size of polyurethane as a sound-absorbing cotton material is generally fixed after foaming, it is difficult to eliminate sound waves in the entire frequency range.

[0005] Chinese invention patent application (publication number: CN110733298A, publication date: 20200131) discloses a tire noise reduction device, which mainly sets a noise reduction structure in the tire cavity of the tire inside the tire. The noise reduction structure sets at least one sound-absorbing material, the sound-absorbing material penetrates to form a hollow air chamber, the sound-absorbing material includes a bonding surface adhered to the inner surface of the tire, and a through surface, a channel is provided through the through surface to communicate the air chamber and face the center of the tire; due to the design of the sound-absorbing material setting the air chamber, the sound wave energy is offset and attenuated, effectively reducing the tire cavity resonance sound. However, in the through channel of the air chamber in the invention patent, the reflection and superposition of sound waves will weaken the sound-absorbing effect. Therefore, this structure still has further optimization space for noise reduction. SUMMARY

[0006] To solve the above technical problems, the purpose of the present application is to provide a tire noise reduction system, which designs one or more larger cylindrical holes inside the sound-absorbing cotton as the main sound-absorbing cavity, which is not communicated with the inner cavity of the tire; secondly, the specific gravity of the sound-absorbing cotton material is increased, that is, the volume of the numerous small sound-absorbing cavities is reduced. Through the implementation of the present application, it is found that the design of the large main sound-absorbing cavity combined with numerous small sound-absorbing cavities can suppress the cavity noise in a wider frequency range.

[0007] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0008] A tire noise reduction system, comprising a pneumatic tire having a cavity, the pneumatic tire having a tread portion, a bead portion, a sidewall portion, the inner wall of the tread portion being provided with a strip-shaped sound-absorbing cotton by adhesive bonding, characterized in that the strip-shaped sound-absorbing cotton is provided with one or more continuous annular holes in the circumferential direction, the strip-shaped sound-absorbing cotton is connected end to end, and the annular holes are also connected end to end to form an annular large sound-absorbing cavity which is not communicated with the inner cavity of the tire; the strip-shaped sound-absorbing cotton is a sponge-like porous material made of high molecular material foaming, and the apparent density is 5kg / m 3 -50kg / m 3 The side wall of the annular hole is communicated with the pores of the strip-shaped sound-absorbing cotton, so that the annular large sound-absorbing cavity and a large number of porous sound-absorbing cavities are communicated.

[0009] As a preferred embodiment, the line connecting the center of gravity of the annular hole and the center of the tire tread is perpendicular to the center auxiliary line of the cross-sectional width of the tire. The setting position of the center of gravity can bring favorable help to the dynamic balance adjustment of the tire.

[0010] As a preferred embodiment, the cross-sectional area of the annular hole accounts for 10-40% of the cross-sectional area of the strip-shaped sound-absorbing cotton, and the apparent density of the strip-shaped sound-absorbing cotton is 5kg / m 3 -20kg / m 3 .

[0011] As a preferred embodiment, the cross-sectional shape of the annular hole is circular, square, equilateral triangle, regular pentagon, regular hexagon or pentagram. Of course, the annular hole of the present application can also include various cross-sectional shapes, including irregular shapes, unequal-sided polygons, etc.

[0012] As a preferred embodiment, the circumscribed circle radius of the cross-sectional shape of the annular hole is Rs, the thickness of the sound-absorbing cotton is Hs, and 2mm≤Rs≤0.5Hs-1mm. If Rs<2mm, the volume of the whole main sound-absorbing cavity is insufficient, and the suppression effect on the cavity noise is weakened; if Rs>0.5Hs-1mm, the volume of the whole sound-absorbing cotton material is reduced, and the number of small cavities is insufficient, and the suppression effect on the cavity noise is also weakened.

[0013] As preferred, the tire cavity height is Hc, the thickness of the sound absorbing cotton is Hs, 5mm≤Hs≤0.8Hc. If Hs<20mm, the number of small sound absorbing cavities inside the sound absorbing cotton is insufficient, and the sound absorbing cotton cannot reduce the cavity noise. If Hs>0.8Hc, the weight of the entire sound absorbing cotton is large, which not only increases the weight of the tire, but also increases the possibility of falling off from the inner wall of the tire during driving.

[0014] As preferred, the cross section of the strip-shaped sound absorbing cotton is square or isosceles trapezoidal.

[0015] As preferred, the high polymer material is selected from one of low-density polyether, polyurethane and polyester. The most preferred is polyurethane super material.

[0016] As preferred, the adhesive is a self-repairing adhesive coating with the functions of anti-puncture repair and adhesion of the sound absorbing cotton. The width of the self-repairing adhesive coating is 50% to 130% of the width of the tread, and the thickness is 0.5 to 3.5mm. The self-repairing adhesive coating used in the application has good adhesion, which can firmly adhere the strip-shaped sound absorbing cotton to the inner surface of the tire. In addition, the self-repairing adhesive coating of the application contains a self-repairing component, which can quickly penetrate into the air leakage position when the tire is punctured, and plug and repair the air leakage hole.

[0017] As preferred, the width of the self-repairing adhesive coating is 100% to 200% of the width of the contact surface of the sound absorbing cotton, and the immersion depth of the self-repairing adhesive coating contained in the sound absorbing cotton is 1 to 3mm.

[0018] The system of the application has one or more large cylindrical holes inside the sound absorbing cotton, which are not communicated with the inner cavity of the tire, and serve as main sound absorbing cavities. In addition, the specific gravity of the sound absorbing cotton material is increased, that is, the volume of the numerous small sound absorbing cavities is reduced. It is found through the implementation of the application that the design of the large main sound absorbing cavities combined with numerous small sound absorbing cavities can suppress the cavity noise in a wide frequency range. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 The figure is a structural schematic diagram of the application. DETAILED DESCRIPTION

[0020] The specific embodiments of the application will be described in detail below with reference to the accompanying drawings.

[0021] As Figure 1The tire noise reduction system shown includes a pneumatic tire with a cavity, the pneumatic tire having a tread portion 1, a bead portion 3, a sidewall portion 2, the inner wall of the tread portion 1 is provided with a strip-shaped sound-absorbing cotton 4 by adhesive 5, the strip-shaped sound-absorbing cotton 4 is a sponge-like porous material made of polyurethane foam, the apparent density of the strip-shaped sound-absorbing cotton 4 is 5kg / m 3 -20kg / m 3 The strip-shaped sound-absorbing cotton 4 has a square cross section, the height of the tire cavity is Hc, the thickness of the sound-absorbing cotton is Hs, 5mm ≤Hs≤0.8Hc. The strip-shaped sound-absorbing cotton 4 is provided with a continuous annular hole 6 in the circumferential direction, the annular hole 6 has a circular cross section, the cross-sectional area of the annular hole accounts for 10-40% of the cross-sectional area of the strip-shaped sound-absorbing cotton, the radius of the circle is Rs, the thickness of the sound-absorbing cotton is Hs, 2mm≤Rs≤0.5Hs-1mm. The line connecting the center of gravity of the annular hole 6 and the center of the tire tread is perpendicular to the center auxiliary line of the cross-sectional width of the tire. The strip-shaped sound-absorbing cotton 4 is connected end to end, and the annular hole 6 is also connected end to end to form an annular main sound-absorbing cavity that does not communicate with the tire cavity; the side wall of the annular hole 6 communicates with the pores of the strip-shaped sound-absorbing cotton 4, so that the annular main sound-absorbing cavity and a large number of porous sound-absorbing cavities are connected in communication.

[0022] The adhesive 5 is a self-repairing coating with the functions of anti-puncture repair and adhesion to sound-absorbing cotton, the width of the self-repairing coating is 50%-130% of the width of the tread, and the thickness is 0.5-3.5mm. The width of the self-repairing coating is 100%-200% of the width of the contact surface of the sound-absorbing cotton, and the depth of the self-repairing coating contained in the sound-absorbing cotton is 1-3mm. The self-repairing coating used in the present application has good adhesion, which can firmly adsorb the strip-shaped sound-absorbing cotton on the inner surface of the tire. In addition, the self-repairing coating of the present application contains a self-repairing component, which can quickly penetrate into the leakage site when the tire is punctured, plug and repair the leakage hole.

[0023] The tire of 205 / 55R16 specification is used as an embodiment, all formulas, materials and structure designs of the tire are the same, only the material density of the sound-absorbing cotton, the radius Rs of the cylindrical sound-absorbing cavity and the thickness Hs of the sound-absorbing cotton are changed. The cavity height of this specification is 60mm. Among them: examples 1-3, comparative examples 1-4 have sound-absorbing cotton structure, comparative example 5 does not have sound-absorbing cotton, comparative example 4 does not have annular main sound-absorbing cavity, and the annular main sound-absorbing cavity of comparative example 3 penetrates the tire cavity.

[0024] Performance test: after GB 4502 test, the sound-absorbing cotton has no shedding phenomenon.

[0025] Noise test: tool: BBM data acquisition system, three-axis acceleration sensor, microphone (microphone). For different schemes of detection tires, on smooth and rough road surface, the car at 80 km / h, to determine the noise level DB under the measurement of 200-300 Hz frequency.

[0026] The specific results are as follows:

[0027]

[0028] The above is the description of the embodiments of the present application, through the above description of the disclosed embodiments, those skilled in the art can realize or use the present application. Various modifications of these embodiments will be apparent to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A tire noise reduction system, comprising a pneumatic tire having a cavity, the pneumatic tire having a tread portion (1), a bead portion (3), and a sidewall portion (2), wherein a strip of sound-absorbing cotton (4) is bonded to the inner wall of the tread portion (1) by an adhesive (5), and characterized in that: The strip-shaped sound-absorbing cotton (4) is provided with more than one continuous annular hole (6) along the circumferential direction. The strip-shaped sound-absorbing cotton (4) is connected end to end, and the annular holes (6) are also connected end to end to form an annular main muffler cavity that is not connected to the inner cavity of the tire. The strip-shaped sound-absorbing cotton (4) is a sponge-like porous material made by foaming a polymer material, and its apparent density is 5kg / m 3 -50kg / m 3 The strip-shaped sound-absorbing cotton (4) has a large number of porous sound-absorbing cavities; the side wall of the annular hole (6) is connected to the porous portion of the strip-shaped sound-absorbing cotton (4), so that the annular main sound-absorbing cavity and the large number of porous sound-absorbing cavities are connected; The line connecting the center of gravity of the annular hole (6) and the center of the tire tread is perpendicular to the center auxiliary line where the tire section width is located; the annular hole (6) occupies 10-40% of the positive cross-sectional area of ​​the strip-shaped sound-absorbing cotton (4); The cross section of the strip-shaped sound-absorbing cotton (4) is a square or an isosceles trapezoid, the cross section of the annular hole (6) is a circle, the radius of the circumscribed circle of the cross section of the annular hole (6) is Rs, the thickness of the sound-absorbing cotton Hs is 2mm≤Rs≤0.5Hs-1mm; the height of the tire cavity is Hc, the thickness of the sound-absorbing cotton Hs is 5mm≤Hs≤0.8Hc.

2. A tire noise reduction system according to claim 1, characterized in that: The apparent density of the strip sound-absorbing cotton is 5kg / m 3 -20kg / m 3 .

3. The tire noise reduction system according to claim 1, characterized in that: The polymer material is selected from one of low-density polyether, polyurethane and polyester.

4. A tire noise reduction system according to any one of claims 1 to 3, characterized in that: The adhesive (5) is a self-repairing rubber coating with both puncture resistance and repair-free function and adhesion to sound-absorbing cotton. The width of the self-repairing rubber coating is set to 50% to 130% of the tread width, and the thickness is 0.5 to 3.5 mm.

5. The tire noise reduction system according to claim 4, characterized in that: The width of the self-repairing rubber coating is set to 100% to 200% of the width of the contact surface with the sound-absorbing cotton, and the impregnation depth of the self-repairing rubber coating impregnated in the sound-absorbing cotton is set to 1 to 3 mm.

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